Method for manufacturing rackets with shock absorbing members with single heating process

ABSTRACT

A method for manufacturing racket with shock absorbing members includes step 1 to form a shaft having two extensions by composite prepreg material; step 2 to wrap two respective shock absorbing members on the two extensions; step 3 to form a head having two tubular portions extending therefrom by composite prepreg material, and steps 4 to insert the two extensions wrapped with the shock absorbing members in the two tubular portions and to heat the combination in a mold.

FIELD OF THE INVENTION

[0001] The present invention relates to a method for manufacturing a racket that has shock absorbing member inserted in the throat portion and/or shaft. The method requires only one time of heating process.

BACKGROUND OF THE INVENTION

[0002] A conventional racket such as a tennis racket generally includes a head, a throat and a shaft. The throat is connected between the frame and the shaft. Strings are connected in the head so as to hit the ball. The impact that the head bears when the ball hits on the head can be huge that the user's hand cannot hold the handle properly. Therefore, manufacturers try to reduce the impact and vibration on the racket. Most of the manufacturers put shock absorbing material on the sides of the head or on the shaft, and that cannot be satisfied because the shock absorbing material does not located at accurate positions and the thickness and weight limit the performance of the shock absorbing material. U.S. Pat. No. 4,284,275 to Fletcher discloses a polyurethane gripping material which is mounted to the handle of rackets. The gripping material has a thickness limitation and absorbs limited vibration. U.S. Pat. No. 5,695,418 to Huang discloses a shock absorbing grip that has the same problems and limitations as U.S. Pat. No. 4,284,275.

SUMMARY OF THE INVENTION

[0003] In accordance with one aspect of the present invention, there is provided a method for manufacturing racket with shock absorbing members and the method comprises the following steps:

[0004] step 1: preparing a shaft which has two extensions extending from one of two ends thereof by composite prepreg material;

[0005] step 2: wrapping two respective shock absorbing members on the two extensions;

[0006] step 3: preparing a head having two tubular portions extending therefrom by composite prepreg material;,

[0007] step 4: inserting the two extensions wrapped with the shock absorbing members in the two tubular portions, and

[0008] step 5: heating the combination in step in a mold under pressure.

[0009] The primary object of the present invention is to provide a method for manufacturing a racket that has shock absorbing members located between the shaft and the throat portion so as to reduce the vibration of the racket.

[0010] The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a flow chart to illustrate a conventional way to manufacture a racket;

[0012]FIG. 2 is a cross sectional view to show the conventional racket is formed in molds;

[0013]FIG. 3 shows the conventional racket;

[0014]FIG. 4 is a flow chart to illustrate the steps of the method of the present invention to manufacture a racket;

[0015]FIGS. 5A and 5B are illustrative view to show the combination of the shaft and the head of the racket made by the method of the present invention;

[0016]FIG. 6 shows two shock absorbing members are wrapped around the two extensions of the throat portion and the racket is heated in a mold;

[0017]FIG. 7 shows the connection of the shock absorbing members, the extensions and the tubular portions;

[0018]FIG. 8 shows the racket made by the method of the present invention;

[0019]FIG. 9 shows the connection of the connection tube, the shock absorbing member and the shaft, and

[0020]FIG. 10 shows a diagram to show the vibration difference between the conventional racket and the racket made by the method of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0021] Referring to FIGS. 1 to 3, the conventional way to manufacture a racket 100 is to form a combination of the head 120 and the shaft 110 of the racket 100 in a mold “-A-“_by heating the material of the head 120 and the shaft 110 under pre-decided pressure. The racket 100 is then separated from the mold “A” and is applied with a sand-grinding process, a coating process and assembling accessory process.

[0022] Referring to FIGS. 4, 5A, 5B, 6, 7 and 8, the method for manufacturing a racket 10 of the present invention comprises the following steps:

[0023] step 1: preparing a shaft 11 having two extensions 13 extending from one of two ends thereof, the shaft 11 and the extensions 13 being made by composite prepreg material;

[0024] step 2: wrapping two respective shock absorbing members 20 on the two extensions 13;

[0025] The absorbing members 20 are made of rubber or silicone which has a fusion temperature higher than that of the composite prepreg material and has a Shore hardness number of 30 to 80.

[0026] step 3: forming a head 12 and the head having two tubular portions 130 extending therefrom, the head 12 and the two tubular portions 130 being made by composite prepreg material;

[0027] steps 4: inserting the two extensions 13 wrapped with the shock absorbing members 20 in the two tubular portions 130;

[0028] step 5: heating the combination in step 4 in a mold “B” under pressure;

[0029] step 6: applying a sand-grinding process to the racket;

[0030] step 7: coating the racket; and

[0031] step 8: assembling accessories to the racket.

[0032] The head 12 and the shaft 11 are made individually so that the size and/or the weight of the two items can be made according to needs so that the manufacturers can manufacture the rackets which meet requirements of attack type players and defense type players. The method requires only one time of heating process.

[0033] Referring to FIG. 9, another method for manufacturing racket with shock absorbing members of the present invention comprises the following steps:

[0034] step 1: preparing a head 12 having a throat portion 121 and a connection section 122 extending from the throat portion 121, the head 12, the throat portion 121 and the connection section 122 being made by composite prepreg material;

[0035] step 2: wrapping a shock absorbing member 20 on the connection section 122;

[0036] step 3: preparing a shaft 11 having an opening defined in one of two ends thereof by composite prepreg material; and

[0037] steps 4: inserting the connection section 122 wrapped with the shock absorbing member 20 in the opening of the shaft 11 and heating the connection part under pressure in a mold.

[0038] The sand-grinding process, the coating process and the process of assembling accessories are also applied to the another embodiment.

[0039] As shown in FIG. 10, taking a point “D” as shown in FIG. 7 to test the vibration of the conventional racket and the racket made by the method of the present invention, two different shock waves are illustrated and which show that the racket made by the method of the present invention dramatically reduces the vibration.

[0040] While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. 

What is claimed is:
 1. A method for manufacturing racket with shock absorbing members, comprising the following steps: step 1: preparing a shaft by composite prepreg material and the shaft having two extensions extending from one of two ends thereof; step 2: wrapping two respective shock absorbing members on the two extensions; step 3: preparing a head by composite prepreg material and the head having two tubular portions extending therefrom;{overscore (,)} steps 4: inserting the two extensions wrapped with the shock absorbing members in the two tubular portions, and step 5: heating the combination in step 4 in a mold under pressure.
 2. The device as claimed in claim 1, wherein the shock absorbing members have a Shore hardness number of 30 to
 80. 3. A method for manufacturing racket with shock absorbing members, comprising the following steps: step 1: preparing a head having a throat portion and a connection section extending from the throat portion, the head, the throat portion and the connection section made by composite prepreg material; step 2: wrapping a shock absorbing member on the connection section; step 3: preparing a shaft which has an opening defined in one of two ends thereof, the shaft made by composite prepreg material;{overscore (,)} step 4: inserting the connection section wrapped with the shock absorbing member in the opening of the shaft, and step 5: heating the combination in step 4 in a mold under pressure.
 4. The device as claimed in claim 3, wherein the shock absorbing member has a Shore hardness number of 30 to
 80. 